A door closer (10) includes an exterior housing (11), a spring assembly (12), a ratchet assembly (13), and a clutch assembly (14). The housing has a central tube (17), drive collar (23), a top end cap (52), and a bottom end cap (65). The drive collar includes an indexing pin channel (41) and indexing pin (42) which includes a pawl (45) having a contact surface (47) and a curved bearing surface (48). The spring assembly includes a shaft (73), a spring stop (80), and a helical torsion spring (106) positioned upon the shaft. The ratchet assembly resides within drive collar and includes ratchet wheel (111) having an annular array of ratchet teeth (112) configured to mesh with the pawl of the indexing pin. Each tooth has an undercut contact surface (113) and a curved bearing surface (114). The clutch assembly includes a bottom disc (120) and a top disc (121).